This invention relates to a crimping apparatus for crimping a metal terminal (having a pair of crimping piece portions extending upwardly respectively from opposite side edges of a base plate portion thereof) to an electric wire.
There is known one conventional crimping apparatus in which an arc-shaped portion 103 with a radius R1 and an arc-shaped portion 104 with a radius R2 are formed on an upper tooth die 102 of a crimper 101, and are disposed respectively at right and left sides of an imaginary straight line A passing through an apex as shown in FIG. 9, and a pair of crimping piece portions 107 of a metal terminal 106 on which an electric wire 105 is placed are press-deformed (that is, press-fastened to the electric wire 105) by the crimper 101 and an anvil 108 (see, for example, JP-UM-A-61-48681).
In JP-UM-A-61-48681, the crimper 101 is so shaped as to enhance the performance. However, the crimper 101 against which the crimping piece portions 107 strike during the press-fastening (press-deforming) operation is liable to be worn at its surface, and it is difficult to maintain a good surface condition for a long period of time. And, when the stable crimping can not be effected because of wear of the crimper 101, there is a fear that the mechanical performance or the electrical performance may be adversely affected. FIG. 10 is a view of the crimper 101 in its unused condition as seen from a direction B of FIG. 9 (standard finishing), and FIG. 11 is an enlarged view showing the surface of the arc-shaped portion (press-fastening portion) 104 of FIG. 10. Even in the unused condition, pits and projections on the surface can be confirmed.